1 files changed, 105 insertions, 0 deletions
diff --git a/initialize.sql b/initialize.sql
new file mode 100644
index 0000000..5a54a7f
--- /dev/null
+++ b/initialize.sql
@@ -0,0 +1,105 @@
+CREATE TABLE IF NOT EXISTS image(
+	sha1     TEXT NOT NULL,     -- SHA-1 hash of file in lowercase hexadecimal
+	width    INTEGER NOT NULL,  -- cached media width
+	height   INTEGER NOT NULL,  -- cached media height
+	thumbw   INTEGER,           -- cached thumbnail width, if known
+	thumbh   INTEGER,           -- cached thumbnail height, if known
+	dhash    INTEGER,           -- uint64 perceptual hash as a signed integer
+	CHECK (unhex(sha1) IS NOT NULL AND lower(sha1) = sha1),
+	PRIMARY KEY (sha1)
+) STRICT;
+
+CREATE INDEX IF NOT EXISTS image__dhash ON image(dhash);
+
+--
+
+CREATE TABLE IF NOT EXISTS node(
+	id       INTEGER NOT NULL,             -- unique ID
+	parent   INTEGER REFERENCES node(id),  -- root if NULL
+	name     TEXT NOT NULL,                -- path component
+	mtime    INTEGER,                      -- files: Unix time in seconds
+	sha1     TEXT REFERENCES image(sha1),  -- files: content hash
+	PRIMARY KEY (id)
+) STRICT;
+
+CREATE INDEX IF NOT EXISTS node__sha1 ON node(sha1);
+CREATE UNIQUE INDEX IF NOT EXISTS node__parent_name
+ON node(IFNULL(parent, 0), name);
+
+CREATE TRIGGER IF NOT EXISTS node__sha1__check
+BEFORE UPDATE OF sha1 ON node
+WHEN OLD.sha1 IS NULL AND NEW.sha1 IS NOT NULL
+AND EXISTS(SELECT id FROM node WHERE parent = OLD.id)
+BEGIN
+	SELECT RAISE(ABORT, 'trying to turn a non-empty directory into a file');
+END;
+
+/*
+Automatic garbage collection, not sure if it actually makes any sense.
+This needs PRAGMA recursive_triggers = 1; to work properly.
+
+CREATE TRIGGER IF NOT EXISTS node__parent__gc
+AFTER DELETE ON node FOR EACH ROW
+BEGIN
+	DELETE FROM node WHERE id = OLD.parent
+	AND id NOT IN (SELECT DISTINCT parent FROM node);
+END;
+*/
+
+--
+
+CREATE TABLE IF NOT EXISTS orphan(
+	sha1 TEXT NOT NULL REFERENCES image(sha1),
+	path TEXT NOT NULL,  -- last occurence within the database hierarchy
+	PRIMARY KEY (sha1)
+) STRICT;
+
+-- Renaming/moving a file can result either in a (ref, unref) or a (unref, ref)
+-- sequence during sync, and I want to get at the same result.
+CREATE TRIGGER IF NOT EXISTS node__sha1__deorphan_insert
+AFTER INSERT ON node
+WHEN NEW.sha1 IS NOT NULL
+BEGIN
+	DELETE FROM orphan WHERE sha1 = NEW.sha1;
+END;
+
+CREATE TRIGGER IF NOT EXISTS node__sha1__deorphan_update
+AFTER UPDATE OF sha1 ON node
+WHEN NEW.sha1 IS NOT NULL
+BEGIN
+	DELETE FROM orphan WHERE sha1 = NEW.sha1;
+END;
+
+--
+
+CREATE TABLE IF NOT EXISTS tag_space(
+	id          INTEGER NOT NULL,
+	name        TEXT NOT NULL,
+	description TEXT,
+	CHECK (name NOT LIKE '%:%'),
+	PRIMARY KEY (id)
+) STRICT;
+
+CREATE UNIQUE INDEX IF NOT EXISTS tag_space__name ON tag_space(name);
+
+-- To avoid having to deal with NULLs, always create this special tag space.
+INSERT OR IGNORE INTO tag_space(id, name, description)
+VALUES(0, '', 'User-defined tags');
+
+CREATE TABLE IF NOT EXISTS tag(
+	id       INTEGER NOT NULL,
+	space    INTEGER NOT NULL REFERENCES tag_space(id),
+	name     TEXT NOT NULL,
+	PRIMARY KEY (id)
+) STRICT;
+
+CREATE UNIQUE INDEX IF NOT EXISTS tag__space_name ON tag(space, name);
+
+CREATE TABLE IF NOT EXISTS tag_assignment(
+	sha1     TEXT NOT NULL REFERENCES image(sha1),
+	tag      INTEGER NOT NULL REFERENCES tag(id),
+	weight   REAL NOT NULL,     -- 0..1 normalized weight assigned to tag
+	PRIMARY KEY (sha1, tag)
+) STRICT;
+
+CREATE INDEX IF NOT EXISTS tag_assignment__tag ON tag_assignment(tag);